Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1388084

[PATCH 3.19.y-ckt 14/66] bonding: fix bond_get_stats()

From Kamal Mostafa <kamal@canonical.com>
Newsgroups linux.kernel
Subject [PATCH 3.19.y-ckt 14/66] bonding: fix bond_get_stats()
Date 2016-04-26 22:50 +0200
Message-ID <rsi5J-5Mq-47@gated-at.bofh.it> (permalink)
References <rshMl-5Dx-3@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw

3.19.8-ckt20 -stable review patch.  If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Eric Dumazet <edumazet@google.com>

[ Upstream commit fe30937b65354c7fec244caebbdaae68e28ca797 ]

bond_get_stats() can be called from rtnetlink (with RTNL held)
or from /proc/net/dev seq handler (with RCU held)

The logic added in commit 5f0c5f73e5ef ("bonding: make global bonding
stats more reliable") kind of assumed only one cpu could run there.

If multiple threads are reading /proc/net/dev, stats can be really
messed up after a while.

A second problem is that some fields are 32bit, so we need to properly
handle the wrap around problem.

Given that RTNL is not always held, we need to use
bond_for_each_slave_rcu().

Fixes: 5f0c5f73e5ef ("bonding: make global bonding stats more reliable")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Andy Gospodarek <gospo@cumulusnetworks.com>
Cc: Jay Vosburgh <j.vosburgh@gmail.com>
Cc: Veaceslav Falico <vfalico@gmail.com>
Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
 drivers/net/bonding/bond_main.c | 65 ++++++++++++++++++++++-------------------
 include/net/bonding.h           |  1 +
 2 files changed, 36 insertions(+), 30 deletions(-)

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 1805087..3a55b0d 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -3168,6 +3168,30 @@ static int bond_close(struct net_device *bond_dev)
 	return 0;
 }
 
+/* fold stats, assuming all rtnl_link_stats64 fields are u64, but
+ * that some drivers can provide 32bit values only.
+ */
+static void bond_fold_stats(struct rtnl_link_stats64 *_res,
+			    const struct rtnl_link_stats64 *_new,
+			    const struct rtnl_link_stats64 *_old)
+{
+	const u64 *new = (const u64 *)_new;
+	const u64 *old = (const u64 *)_old;
+	u64 *res = (u64 *)_res;
+	int i;
+
+	for (i = 0; i < sizeof(*_res) / sizeof(u64); i++) {
+		u64 nv = new[i];
+		u64 ov = old[i];
+
+		/* detects if this particular field is 32bit only */
+		if (((nv | ov) >> 32) == 0)
+			res[i] += (u32)nv - (u32)ov;
+		else
+			res[i] += nv - ov;
+	}
+}
+
 static struct rtnl_link_stats64 *bond_get_stats(struct net_device *bond_dev,
 						struct rtnl_link_stats64 *stats)
 {
@@ -3176,43 +3200,23 @@ static struct rtnl_link_stats64 *bond_get_stats(struct net_device *bond_dev,
 	struct list_head *iter;
 	struct slave *slave;
 
+	spin_lock(&bond->stats_lock);
 	memcpy(stats, &bond->bond_stats, sizeof(*stats));
 
-	bond_for_each_slave(bond, slave, iter) {
-		const struct rtnl_link_stats64 *sstats =
+	rcu_read_lock();
+	bond_for_each_slave_rcu(bond, slave, iter) {
+		const struct rtnl_link_stats64 *new =
 			dev_get_stats(slave->dev, &temp);
-		struct rtnl_link_stats64 *pstats = &slave->slave_stats;
-
-		stats->rx_packets +=  sstats->rx_packets - pstats->rx_packets;
-		stats->rx_bytes += sstats->rx_bytes - pstats->rx_bytes;
-		stats->rx_errors += sstats->rx_errors - pstats->rx_errors;
-		stats->rx_dropped += sstats->rx_dropped - pstats->rx_dropped;
-
-		stats->tx_packets += sstats->tx_packets - pstats->tx_packets;;
-		stats->tx_bytes += sstats->tx_bytes - pstats->tx_bytes;
-		stats->tx_errors += sstats->tx_errors - pstats->tx_errors;
-		stats->tx_dropped += sstats->tx_dropped - pstats->tx_dropped;
-
-		stats->multicast += sstats->multicast - pstats->multicast;
-		stats->collisions += sstats->collisions - pstats->collisions;
-
-		stats->rx_length_errors += sstats->rx_length_errors - pstats->rx_length_errors;
-		stats->rx_over_errors += sstats->rx_over_errors - pstats->rx_over_errors;
-		stats->rx_crc_errors += sstats->rx_crc_errors - pstats->rx_crc_errors;
-		stats->rx_frame_errors += sstats->rx_frame_errors - pstats->rx_frame_errors;
-		stats->rx_fifo_errors += sstats->rx_fifo_errors - pstats->rx_fifo_errors;
-		stats->rx_missed_errors += sstats->rx_missed_errors - pstats->rx_missed_errors;
-
-		stats->tx_aborted_errors += sstats->tx_aborted_errors - pstats->tx_aborted_errors;
-		stats->tx_carrier_errors += sstats->tx_carrier_errors - pstats->tx_carrier_errors;
-		stats->tx_fifo_errors += sstats->tx_fifo_errors - pstats->tx_fifo_errors;
-		stats->tx_heartbeat_errors += sstats->tx_heartbeat_errors - pstats->tx_heartbeat_errors;
-		stats->tx_window_errors += sstats->tx_window_errors - pstats->tx_window_errors;
+
+		bond_fold_stats(stats, new, &slave->slave_stats);
 
 		/* save off the slave stats for the next run */
-		memcpy(pstats, sstats, sizeof(*sstats));
+		memcpy(&slave->slave_stats, new, sizeof(*new));
 	}
+	rcu_read_unlock();
+
 	memcpy(&bond->bond_stats, stats, sizeof(*stats));
+	spin_unlock(&bond->stats_lock);
 
 	return stats;
 }
@@ -4021,6 +4025,7 @@ void bond_setup(struct net_device *bond_dev)
 	struct bonding *bond = netdev_priv(bond_dev);
 
 	spin_lock_init(&bond->mode_lock);
+	spin_lock_init(&bond->stats_lock);
 	bond->params = bonding_defaults;
 
 	/* Initialize pointers */
diff --git a/include/net/bonding.h b/include/net/bonding.h
index 983a94b..bf97043 100644
--- a/include/net/bonding.h
+++ b/include/net/bonding.h
@@ -212,6 +212,7 @@ struct bonding {
 	 * ALB mode (6) - to sync the use and modifications of its hash table
 	 */
 	spinlock_t mode_lock;
+	spinlock_t stats_lock;
 	u8	 send_peer_notif;
 	u8       igmp_retrans;
 #ifdef CONFIG_PROC_FS
-- 
2.7.4

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[3.19.y-ckt stable] Linux 3.19.8-ckt20 stable review Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:30 +0200
  [PATCH 3.19.y-ckt 09/66] net: validate variable length ll headers Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:30 +0200
  [PATCH 3.19.y-ckt 53/66] x86/mm/xen: Suppress hugetlbfs in PV guests Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:30 +0200
  [PATCH 3.19.y-ckt 63/66] Input: pmic8xxx-pwrkey - fix algorithm for converting trigger delay Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:30 +0200
  [PATCH 3.19.y-ckt 45/66] drm/radeon: add a quirk for a XFX R9 270X Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:30 +0200
  [PATCH 3.19.y-ckt 62/66] net: bcmgenet: device stats are unsigned long Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:30 +0200
  [PATCH 3.19.y-ckt 21/66] ARM: OMAP2+: hwmod: Fix updating of sysconfig register Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:30 +0200
  [PATCH 3.19.y-ckt 38/66] crypto: sha1-mb - use corrcet pointer while completing jobs Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 44/66] powerpc: Update TM user feature bits in scan_features() Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 18/66] ipv4: l2tp: fix a potential issue in l2tp_ip_recv Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 33/66] usb: xhci: fix wild pointers in xhci_mem_cleanup Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 39/66] crypto: ccp - Prevent information leakage on export Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 43/66] powerpc: Update cpu_user_features2 in scan_features() Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 48/66] ALSA: pcxhr: Fix missing mutex unlock Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 47/66] futex: Acknowledge a new waiter in counter before plist Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 36/66] USB: uas: Add a new NO_REPORT_LUNS quirk Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 50/66] drm/radeon: forbid mapping of userptr bo through radeon device file Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 34/66] usb: xhci: fix xhci locking up during hcd remove Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 46/66] futex: Handle unlock_pi race gracefully Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 30/66] usb: xhci: applying XHCI_PME_STUCK_QUIRK to Intel BXT B0 host Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 35/66] xhci: fix 10 second timeout on removal of PCI hotpluggable xhci controllers Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 27/66] ALSA: hda - Fix regression of monitor_present flag in eld proc file Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 22/66] drm/qxl: fix cursor position with non-zero hotspot Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 42/66] powerpc: scan_features() updates incorrect bits for REAL_LE Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 23/66] Input: gtco - fix crash on detecting device without endpoints Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 41/66] ALSA: hda/realtek - Add ALC3234 headset mode for Optiplex 9020m Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 59/66] bpf/verifier: reject invalid LD_ABS | BPF_DW instruction Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 31/66] xhci: resume USB 3 roothub first Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 37/66] usb: hcd: out of bounds access in for_each_companion Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 32/66] usb: host: xhci: add a new quirk XHCI_NO_64BIT_SUPPORT Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 29/66] lib: lz4: fixed zram with lz4 on big endian machines Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 40/66] video: ARM CLCD: runtime check for Versatile Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 26/66] nl80211: check netlink protocol in socket release notification Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 28/66] dmaengine: dw: fix master selection Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 25/66] ALSA: usb-audio: Skip volume controls triggers hangup on Dell USB Dock Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 08/66] udp6: fix UDP/IPv6 encap resubmit path Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:50 +0200
  [PATCH 3.19.y-ckt 11/66] macvtap: always pass ethernet header in linear Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:50 +0200
  [PATCH 3.19.y-ckt 16/66] qmi_wwan: add "D-Link DWM-221 B1" device id Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:50 +0200
  [PATCH 3.19.y-ckt 10/66] sh_eth: fix NULL pointer dereference in sh_eth_ring_format() Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:50 +0200
  [PATCH 3.19.y-ckt 01/66] usbnet: cleanup after bind() in probe() Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:50 +0200
  [PATCH 3.19.y-ckt 05/66] sctp: lack the check for ports in sctp_v6_cmp_addr Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:50 +0200
  [PATCH 3.19.y-ckt 02/66] tunnel: Clear IPCB(skb)->opt before dst_link_failure called Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:50 +0200
  [PATCH 3.19.y-ckt 04/66] net: qca_spi: clear IFF_TX_SKB_SHARING Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:50 +0200
  [PATCH 3.19.y-ckt 17/66] rtnl: fix msg size calculation in if_nlmsg_size() Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:50 +0200
  [PATCH 3.19.y-ckt 15/66] xfrm: Fix crash observed during device unregistration and decryption Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:50 +0200
  [PATCH 3.19.y-ckt 20/66] HID: usbhid: fix inconsistent reset/resume/reset-resume behavior Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:50 +0200
  [PATCH 3.19.y-ckt 14/66] bonding: fix bond_get_stats() Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:50 +0200
  [PATCH 3.19.y-ckt 07/66] cdc_ncm: toggle altsetting to force reset before setup Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:50 +0200
  [PATCH 3.19.y-ckt 19/66] ipv6: l2tp: fix a potential issue in l2tp_ip6_recv Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:50 +0200
  [PATCH 3.19.y-ckt 12/66] farsync: fix off-by-one bug in fst_add_one Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:50 +0200
  [PATCH 3.19.y-ckt 06/66] qmi_wwan: add Sierra Wireless EM74xx device ID Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:50 +0200

csiph-web